Ventral control surfaces are needed for stability and yaw control, but couldn't the enlarged vertical stabilizers to make up for that? The J-31 didn't need them.
Why did they add an inner frame to the canopy?
The J-20 is definitely looking good. Can't wait to see the true LRIP variant. With this bird and the J-10B in large numbers, the PLAAF would be second only to the USAF. I like (hope) to see the J-20 at Red Flag someday which incidently will begin very soon at Nellis AFB.
IF USN can invite PLAN to RIMPAC, USAF can invite PLAAF to RedFlag. Hopefully someday they will and hopefully the political relations between the US and China allows that.
I think tht picture has been posted earlier. this one is cropped. The picture is actually of a J-10S